<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>启动页</title>
</head>

<body>
  <div class="container">
    <!-- <div class="card" style="--i: -4">1</div> -->
    <!-- <div class="card" style="--i: -3">2</div> -->
    <!-- <div class="card" style="--i: -2">3</div> -->
    <!-- <div class="card" style="--i: -1">4</div> -->
    <div class="card" style="--i: 0;"  onclick="openHtml('auto-teacher')">师 者</div>
    <!-- <div class="card" style="--i: 1">6</div> -->
    <!-- <div class="card" style="--i: 2">7</div> -->
    <!-- <div class="card" style="--i: 3">8</div> -->
    <!-- <div class="card" style="--i: 4">9</div> -->
  </div>
  <script>
    function openHtml(files) {
        window.open('./'+files+'/index.html')
    }
  </script>
</body>
<style>
    @import url('https://fonts.googleapis.com/css?family=Poppins:200,300,400,500,600,700,800,900&display=swap');

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}

body {
  min-height: 100vh;
  background-color: white;
  color: #ccc;
  
  display: flex;
  justify-content: center;
  align-items: center;
  overflow-x: hidden;
}

.container {
  position: relative;

  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.container .card {
  position: absolute;
  width: 240px;
  height: 320px;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #5e5cfc;
  /* -200deg -150deg ... 0deg 50deg 100deg ... */
  filter: hue-rotate(calc(var(--i) * 50deg));
  border: 10px solid rgba(0, 0, 0, 0.1);
  border-radius: 8px;
  box-shadow: 0 15px 50px rgba(0, 0, 0, 0.1);

  color: rgba(0, 0, 0, 0);
  font-size: 4em;
  font-weight: 700;
  text-align: center;

  transition: 0.5s;
  cursor: pointer;
  user-select: none;
}

.container:hover .card {
  color: rgba(0, 0, 0, 0.7);
  box-shadow: 0 15px 50px rgba(0, 0, 0, 0.25);

  /* rotate: -20deg -15deg ... 0deg 5deg 10deg ... translate: -480px -360px ... 0 120px 240px ...*/ 
  transform: rotate(calc(var(--i) * 5deg)) translate(calc(var(--i) * 120px), -50px);
}

.container:active .card {
  background-color: #333;
}

.container .card:active {
  background-color: #5e5cfc;
  translate: calc(var(--i) * 20px) -50px;
  z-index: 100;
}


@media screen and (max-width: 768px) {
  .container .card {
    scale: .5;
  }
}

@media screen and (max-width: 576px) {
  .container .card {
    scale: .3;
  }
}

</style>

</html>